Conventional practice with telephone equipment typically supports the shipment of phones to various countries by developing different models of the phone for each unique loss plan and each keyboard scanning requirement. As a result it becomes necessary to develop a large number of different models of a particular phone if world-wide distribution of the phone is to occur.
It can be appreciated that a desirable goal is the provision of a telephone which meets all of the safety agency requirements of all countries, and which also allows the unique, country-specific, parameters of the phone to be downloaded from a Private Automatic Branch Exchange, or PABX, to which the phone is coupled. Included among these unique parameters are a loss plan or plans, keyscanning requirements, feedback tone requirements and companding method (A-Law or u-Law).
It can also be appreciated that if it is desirable to download and store the telephone'loss plan then it would also be desirable to download and store other parameters that may be unique to a particular phone, such as the phone's programmable dialing sequences, class of service, and so on. This downloading of unique phone parameters would allow for an improved phone system. Additionally it may be desirable to locally store the phone's serial number in non-volatile memory and read back the serial number in order to assist in capital asset tracking and as an aid in identifying the phone, and possibly the user of the phone, if the phone is moved to a different location within a facility.
It is therefore one object of the invention to provide a telephone which allows these and other parameters to be downloaded to and stored within the telephone.
It is another object of the invention to provide a protocol which enables the downloading of parameters from a telephone switching apparatus to a telephone.
It is another object of the invention to provide a protocol which enables the downloading of information from a telephone switching apparatus to a telephone and the subsequent reading back by the telephone switching apparatus of the previously stored information.
It is one further object of the invention to provide apparatus for and a method of bidirectionally communicating between a telephone and a PABX which includes the local non-volatile storage of downloaded and other parameters within the telephone.